<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>18.下拉菜单</title>
    <link rel="stylesheet" href="css/bootstrap.min.css">
</head>
<body>

<div class="dropdown">
  <button type="button" class="btn dropdown-toggle" id="dropdownMenu1" data-toggle="dropdown">主题
    <span class="caret"></span>
  </button>
  <ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu1">
    <li role="presentation" class="dropdown-header">下拉菜单标题</li>
    <li role="presentation">
      <a role="menuitem" tabindex="-1" href="#">Java</a>
    </li>
    <li role="presentation">
      <a role="menuitem" tabindex="-1" href="#">数据挖掘</a>
    </li>
    <li role="presentation">
      <a role="menuitem" tabindex="-1" href="#">数据通信/网络</a>
    </li>
    <li role="presentation" class="divider"></li>
    <li role="presentation" class="dropdown-header">下拉菜单标题</li>
    <li role="presentation">
      <a role="menuitem" tabindex="-1" href="#">分离的链接</a>
    </li>
  </ul>
</div>


<script type="text/javascript" src="js/jquery.min.js"></script>
<script type="text/javascript" src="js/bootstrap.min.js"></script>
</body>
</html>